The present invention relates to improvements in and relating to heading indicating apparatus for vehicles of the type which indicates the heading or the direction of travel of a moving object such as a vehicle digitally or analogically in accordance with the output signals of a direction-finding sensor.
Known apparatus of the type in which the heading of a vehicle is detected and indicated by a direction-finding sensor such as is disclosed in Japanese Laid Open Patent Application No. 54-21889, includes two types, i.e., the analog type in which as disclosed in Japanese Laid Open patent application No. 54-28165, a pair of windings are wound to cross each other at right angles on a permanent magnet magnetized symmetrically with respect to a rotary shaft so that the output signals of a pair of output windings of a direction-finding sensor are respectively applied to the windings on the magnet and the permanent magnet is rotated thereby indicating the direction of the direction-finding sensor with respect to the earth's magnetic field or the direction of travel of the vehicle, and the digital type in which the direction-finding sensor includes N output windings wound on its magnetic core so as to divide it into 2N equal parts so that in accordance with the position of one of the output windings generating the highest or lowest output signal, the direction of travel of a vehicle is indicated digitally by one of the 2N headings or directions.
Of these prior art apparatus, the analog type is disadvantageous in that if the friction of the bearings on the rotary shaft of the permanent magnet is large, a large heading indication error will be caused and that it is difficult to position the apparatus normal to the line of vision of the driver as in the case of various automobile meters. The digital type of indicating the heading in accordance with one of the 2N headings is disadvantageous in that to increase the number of headings indicated, it is necessary to increase the number of the output windings of a direction-finding sensor, thus making it difficult to ensure reduced size and simplified manufacture of the direction-finding sensor.